System and method for making wallboard

ABSTRACT

A method of making wallboard including the steps of providing an unfinished length of wallboard that has a recess along its longitudinal edges by conveying it upon a conveyor in a first direction in a step, forming recesses in the unfinished length of wallboard at both lateral edges thereof, selecting an apparatus for forming the recess from a plurality of device for forming the recess, forming the recess with the selected apparatus, and separating the unfinished length of wallboard at a location of the recess to form finished lengths of wallboard, such that the finished lengths of wallboard have recessed lateral edges. Also disclosed is a system for performing the method.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 60/736,123, filed Nov. 9, 2005, the contents of whichare incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to gypsum board, and more specificallyto a method and apparatus for providing recessed portions on the lateraledges of wallboard.

BACKGROUND OF THE INVENTION

Conventional gypsum wallboard or drywall is typically manufactured froma gypsum plaster slurry which is put between two layers of paper. Morespecifically, in the conventional method, a wet slurry of gypsum ispoured on a conveyor between two layers of paper, and the slurry isallowed a certain amount of time to set. In gypsum wallboard, the twolayers of paper contain the slurry and provide the tensile strengthrequired in installation and use.

In at least some known fabrication methods, the conveyor is a closedloop conveyor that can travel at speeds of four hundred feet per minuteor faster. The conveyor enables the wallboard to be fabricated usingrolls of paper and accordingly, includes at least a longitudinal edgeforming system, a cutting system, and a drying system. The edge formingsystem uses wedge shaped raised edges along the conveyor that createrecessed areas along the longitudinal edges in the face of the wallboardprior to the wallboard being fully cured. When the wallboard is latercut to size and installed, the recesses are filled with wallboardcompound, taped over, and finished to produce a smooth joint.

The cutting system enables the wallboard to be cut into predetermineddiscrete lengths such that substantially rectangular wallboard membersare formed. The cutting system is adjustable to allow different lengthsof wallboard to be cut without substantial interruption of themanufacturing operation.

After being cut, the wallboard members are moved away from the cuttingstation to a loading area where they are loaded into a drying system todry the cut wallboard members.

Known wallboard includes recessed areas that extend along both of theopposed longitudinal edges of the wallboard. The recessed areas areformed by the raised edges on the conveyor. The recessed areas are inthe shape of inclined planes that taper from the face of the wallboardto the longitudinal edges and have a maximum depth at the side edges ofabout 0.090″ below the face of the wallboard.

When the wallboard is cut by the cutting system, panels of conventionalwallboard are formed which are bordered by the opposed recessedlongitudinal edges and by a pair of lateral non-recessed edges thatconnect the longitudinal edges. More specifically, the wallboard istypically cut such that the panels are fabricated with a longitudinallength that is commonly eight feet, ten feet, twelve feet, fourteenfeet, and sixteen feet or longer. Additionally, wallboard panels aremade in thicknesses that are commonly ¼″, ⅜″, ½″ and ⅝″ thick. Formaximum efficiency and conservation of plant space, the same line musthave the capability of fabricating all of the different lengths ofwallboard without a major shutdown of the line.

During installation, depending on the length of the wall being formed bythe wallboard, wallboard panels are typically positioned forinstallation such that the longitudinal edges are parallel to the floor,an installation known as a “horizontal orientation”. In thisinstallation, a longitudinal recess of a first panel is adjacent to alongitudinal recess of the adjacent panel. This forms a longitudinalrecessed joint. A wallboard compound fill material and tape are thenused to seal the recessed joint formed by the recessed longitudinaledges of the panels. Specifically, the recessed areas of the joints arefilled with the wallboard compound, taped and smoothed across the joint,such that the joint is covered without the compound creating anunsightly bulge extending outwardly between the panels. Installing thewallboard panels such that the longitudinal length extends horizontallyalong a wall parallel to the floor, rather than vertically andsubstantially perpendicularly to the floor, facilitates fasterinstallation time of the wallboard panels, and faster finishing time ofthe installed wallboard panels. In addition, when wallboard is installedin a vertical orientation, installation and labor costs may be increasedas the installers and tapers must use ladders for installation andfinishing.

When wallboard panels are installed on longer walls and ceilings,because the recessed areas only extend along two longitudinal edges ofeach panel, a butt joint may be formed between the lateral edges of twoadjacent panels. Such joints must still be covered with tape andcompound, but because the lateral edges do not include a recessed area,the joint compound must be spread over a wider area than those of thelongitudinal joints to facilitate blending the butt joints into the wallsurface without creating unsightly bulges.

Adding to the difficulty of creating recessed area in lateral edges ofwallboard panels is that the panels are made in continuous lengths,which are then cut to size after the wallboard panel has fully cured. Itis very difficult to create the recessed areas in the wallboard panelafter the gypsum is fully cured and a particular problem has beendelamination of the paper from the gypsum core.

SUMMARY OF THE INVENTION

The present invention comprises a method of making wallboard comprisingthe steps of a) providing an unfinished length of wallboard that has arecess along its longitudinal edges by conveying it upon a conveyor in afirst direction in a step, b) forming recesses in the unfinished lengthof wallboard at both lateral edges thereof, c) selecting an apparatusfor forming the recess from a plurality of devices for forming therecess, d) forming the recess with the selected apparatus, and e)separating the unfinished length of wallboard at a location of therecess to form finished lengths of wallboard, such that the finishedlengths of wallboard have recessed lateral edges.

The present invention provides a device for forming the recesses in anunfinished length of wallboard. The device comprises a first presslocated at a first lateral edge of the unfinished length of wallboard,and a second press located at a second lateral edge of the unfinishedlength of wallboard opposite the first lateral edge. A third press islocated between the first and second press. As unfinished lengths ofwallboard are fed into the first, second and third presses, the firstpress forms a recess along the first lateral edge, the second pressforms a recess along the second lateral edge and the third press forms arecess in the wallboard generally parallel to the first recess andbetween the first and second lateral edges.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is plan view of gantry having a plurality of drywall pressesaccording to an embodiment of the present invention;

FIG. 2 is perspective view of a drywall press according to an embodimentof the present invention;

FIG. 3 is perspective view of an upper press assembly according to anembodiment of the present invention;

FIG. 4 is perspective view of a lower press assembly according to anembodiment of the present invention;

FIG. 5 is perspective view of an upper shoe assembly according to anembodiment of the present invention in an extended position;

FIGS. 6A-6F are views of an upper shoe according to an embodiment of thepresent invention;

FIG. 7 is perspective view of an upper shoe assembly according to anembodiment of the present invention in a retracted position;

FIGS. 8A-8D are views of a lower shoe according to an embodiment of thepresent invention;

FIG. 9 is perspective view of a lower shoe assembly according to anembodiment of the present invention;

FIGS. 10A-10C are views of a pin according to an embodiment of thepresent invention;

FIG. 11 is a partial side view of a length of wallboard passing throughan upper and lower press assembly according to an embodiment of thepresent invention; and

FIG. 12 is a side view of a length of wallboard passing through an upperand lower press assembly according to an embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail preferred embodiments of the invention with the understandingthat the present disclosure is to be considered as an exemplification ofthe principles of the invention and is not intended to limit the broadaspect of the invention to the embodiments illustrated.

Referring to FIG. 1, a preferred embodiment of the present inventioncomprises a press 20 for forming of one or more recessed lengths inpartially cured gypsum wallboard such that when the partially curedwallboard is cut into finished lengths, the lateral edges of thefinished lengths have recessed edges on all four edges of the board. Forthe purposes of the present invention, a recess can be a tapered ornon-tapered recess. The invention preferably performs this pressfunction in partially cured gypsum wallboard panels after gypsum slurryhas been applied to paper backing but before the wallboard is sent toovens to fully cure. However, it is within the scope of the presentinvention to form recesses along cured gypsum before it is cut intofinished lengths or to sheets of cured gypsum wallboard that has alreadybeen cut to finished lengths.

In the preferred aspect, where the gypsum is only partially cured andthe wallboard not cut to finished lengths, the recessed areas are formedalong the lateral edges of the uncut wallboard and also in severallocations along the length of the uncut wallboard. The locations of therecesses on the length of the uncut wallboard will vary depending uponwhether eight foot lengths, nine foot lengths, ten foot lengths, etc. ofwallboard, or combinations of length thereof, are being produced.Typically, the length of uncut and partially cured wallboard that issent to ovens to be fully cured is 32′, although other lengths may beproduced in various gypsum wallboard plants. The 32′ foot length, orother appropriate length, is referred to as the unfinished length. Inthe event of 32′ lengths, it is preferably to have presses located at 0′(i.e. the lateral edge), 8′, 9′ 10′, 12′, 14′, 16′, 18′, 20′, 22′, 23′,24′, 27′ and 32′ (i.e. the opposite lateral edge). The present inventionaccomplishes this by providing presses at each location indicated.Alternatively, a smaller number of presses are provided that arepositionable on the support system to the various required locations.Additionally, the presses are easily removable so that a press may beremoved for repair and maintenance. By feeding the 32′ length into thepress and forming recesses in the ends and at one or more locationsalong the length of the wallboard, recesses running the width are formedtherein such that every common length of wallboard can be manufacturedwith lateral edge tapers at the finished wallboard lengths.

The presses 20 each comprise an upper press assembly 22 and a lowerpress assembly 24. Wallboard 26 passes between the upper and lower pressassemblies 22 and 24. The upper press assemblies 22 are moveable from anupper position where the upper press assemblies 22 do not contact theuncut wallboard and a lower position where the upper press assemblies 22come into contact with the uncut wallboard. Because the recesses aremost preferably only about 0.090″ deep, the upper press assemblies 22are infinitely adjustable in the vertical direction such that fineadjustment can be made to adjust for tolerances in the thickness of thewallboard and also to accommodate wallboard of different nominalthicknesses. The proper adjustment of the height of the upper pressassembly may be detected by either a laser measure or by physicallycontacting the wallboard, for example with a roller that measures theprecise thickness of the wallboard. The upper presses 22 are allindividually adjustable to properly control recess depth as thewallboard moves through the presses. As can been seen in FIG. 1, fourupper press assemblies 22 have been lowered in position at 0′, 12′, 22′and 32′ to make wallboard of 10′ and 12′ lengths.

FIG. 2 shows the upper press assembly 22, the lower press assembly 24and a takeout conveyor 28 to remove the wallboard from the press. Anupper surface of the takeout conveyor 28 is preferably in a plane lowerthan the upper surface of the lower press assembly 24 so that thewallboard 26 will move away from the upper press assembly 22 as it exitsthe lower press assembly 24. Lengths of wallboard 26 are shown betweenthe upper and lower press assemblies 22 and 24, and the press assemblies22 and 24 and takeout conveyor 28 move the wallboard in a directionindicated by arrow A.

As shown in FIG. 3, the upper press assembly 22 comprises two spacedapart plates 30 and 32 attached to one another to form an upper plateassembly 34. Riding upon the upper plate assembly 34 are a plurality ofupper shoe assemblies 36. The upper shoe assemblies 36 are attached toone another end-to-end and form a loop around the upper plate assembly34. A large sprocket 38 is located at a first end 40 of the plateassembly 36, and a small sprocket 42 is located at an opposite, secondend 44 of the plate assembly 36. The sprockets are located between theplates 30 and 32. One or both of the sprockets 38 and 42 are powered tocause the upper shoe assemblies 36 to rotate about the upper plateassembly 34 in the direction shown by the arrows B. Also provided is ashoe support bar 46 that maintains the upper shoe assemblies 36 adjacentthe upper plate assembly 34 as the upper shoe assemblies 36 travel alongthe bottom portion of the upper plate assembly 34 until the upper shoeassemblies 36 are out of contact with the wallboard as they extendaround the large sprocket 38, as further described below.

The lower press assembly 24 is shown in FIG. 4 and comprises first andsecond plates 48 and 50 attached to one another and spaced apart fromone another to form a lower plate assembly 52 having a first end 56 anda second end 60. Mounted upon the lower plate assembly 52 are aplurality of lower shoe assemblies 54. The lower shoe assemblies 54extend around the lower plate assembly 52 to form a loop. The lower shoeassemblies 54 are further driven by one or both of a first sprocket 58at the first end 56 and a second sprocket (not shown) at a second end60.

Referring to FIGS. 5 and 6A-6F, the upper shoe assemblies 36 of theupper press assembly 22 comprise a forming plate 64. The forming plate64 comprises two upstanding outer walls 66 and 67. Between the walls 66and 67 are located two support blocks 68. Each support block 68 definesa bore 70 that is in line with bores 72 defined in each outer wall 66and 67. The support blocks 68 each further define an arcuate stopportion 74. Mounted within the bores 70 and 72 is a pin 76. The pin 76captures three roller bearings 78 as well as two chain side plates 80.Another pin 82 captures three more roller bearings 84 and an oppositeend of the chain side plate 80. The pin 82 is associated with the uppershoe assembly 36 by virtue of the pin 82 extending into two slots 85that are formed within the side walls 66 and 67 of the forming plate 64.The bearings 84 are spaced apart by collars 75 placed over the pin 82and between the bearings 84.

As a result of pin 82 being located within the slots 84, the formingplate 64 is allowed to pivotally move about the pin 76 move from afirst, open position as shown in FIG. 6 to a second, closed position asshown in FIG. 7, making the distance between the bearing 82 and a bottomsurface 90 of the forming plate 64 variable.

The upper shoe assembly 36 further comprises a pair of shoe alignmentbearings 86 mounted on the support blocks 68. Additionally, shoe pivotbearings 88 are attached to each wall 66 and 67.

In the most preferred embodiment, the bottom surface 90 of the formingplate 64 is 6½″ wide as viewed from FIG. 6D and FIG. 6F. A flat pad 92is centered on the bottom surface 90 of the forming plate 64 isapproximately 1¼″ wide. First tapered portions 94 taper at about a threedegree angle from the flat pad 92 for about 1¼″ from the center of thebottom surface 90. Second tapered portions 96 taper at about a onedegree angle from the flat pad 92 from the first tapered portion 94 toeither edge of the forming plate 64. The multiple tapered surfacesprevent bulging of the wallboard it the edge of the forming plate 64.

Multiple upper shoe assemblies 36 are attached to one another throughthe use of additional chain side plates 80 which extend from the pin 82to a pin 76 of an adjacent, trailing upper shoe assembly 36 and a chainside plate 80 that extends from a pin 76 of the upper shoe assembly 36to the pin 82 of an adjacent, preceding upper shoe assembly 36. Theforming plates 64 further comprise a front support surface 69 and a rearsupport surface 71. The point where the support surface 69 meets thebottom surface 90 is located at or behind an imaginary line Z—Z whichpasses though the center of the aligned bores 70 and 72 andperpendicular to the surface 90. When the upper shoe assemblies 36 areattached to one another with the chain side plates 80, the front supportsurface 69 of one upper shoe assembly 36 rests upon the rear supportsurface 71 of an adjacent upper shoe assembly 36. In this manner thebottom surfaces 90 of each shoe provide a consistent surface in whichthe flat pads 92, first tapered portions 94 and second tapered portions96 of the attached upper shoe assemblies 36 align and are coplanar toform a consistent surface even with significant force applied to thesurface 90 of each forming plate 64.

Referring to FIGS. 8A-D and 9, the lower shoe assemblies 54 comprise asupport plate 98. The support plate 98 has a flat lower surface 100 andtwo upwardly extending sidewalls 102 and 103. The support plate 98 alsocomprises a pair of support blocks 104 each having aligned bores 106defined therein which align with bores 108 defined within the sidewalls102 and 103. Inserted within the aligned bores 106 and 108 is a pin 110.The pin 110 retains three roller bearings 120 and two chain side plates202 to the support plate 98. Also attached to the two support blocks 104are alignment bearings 106. The chain side plates 202 each attach to apin 110 of a preceding, adjacent support plate 98 and the chain sideplates 202 of a following, adjacent support plate 98 attach to the pin110 of the present support plate 98, and so on, to create a chain.

The forming plate 98 further defines an arcuate surface 204 and a rearsupport shelf 206. When multiple lower shoe assemblies 54 are placed areattached to one another by the chain side plates 80 the arcuate surface204 of a lower shoe assembly 54 rests upon the rear support shelf 206 ofan adjacent lower shoe assembly 54. As a result, lower surfaces 100 ofthe lower shoe assemblies 54 form a flat surface upon which a sheet ofpartially cured wallboard 26 may rest without deformation of thewallboard 26.

Referring to FIGS. 10A-C, the pins 76, 82 and 110 are preferablyidentical and are described with respect to representative pin 76. Thepin 76 has central bore 130 that is threaded at either end. The pin 76further has annular grooves 132 at the locations that correspond to themounting of bearings thereon. Connecting bores 134 extend through thepin 76 at the location of the annular grooves 132 to provide a path fromthe annular grooves 132 to the central bore 130. In this manner, greasefittings may be threaded into the pin 76 at the central bore 130 toprovide grease through the central bore 130 to the connecting bores 134to the annular grooves 132 and to lubricate the bearings mounted on thepin 76. Annular grooves 136 are sized to accept retainer clips to retainthe pins 76 in the forming plate 64 or support plate 98, as the case maybe.

The upper shoe assemblies 36 of the upper press assembly 22 aremaintained and aligned on the plates 30 and 32 by the shoe alignmentbearings 86. The shoe alignment bearings 86 contact inner surfaces 120and 122 of the plates 30 and 32, respectively, of the upper pressassembly 22. Likewise, the lower shoe assemblies 54 of the lower pressassembly 24 are maintained and aligned on the plates 48 and 50 by thealignment bearings 106. The alignment bearings 106 contact innersurfaces 124 and 128 of the plates 48 and 50 of the lower press assembly24.

FIG. 12 shows a simplified view of the interaction of the upper shoeassemblies 36 and the lower shoe assemblies 54 as they are moved aboutthe perimeter of the plates 30 and 32 and the plates 48 and 50,respectively. The upper shoe assemblies 36, as they pass the around thesecond end 44 of the upper press assembly 22, pivot outwardly. In thismanner, the surfaces 90 of the upper shoe assemblies 36 become parallelto the wallboard 26 at the point where the surfaces 90 first makecontact with the wallboard. The upper shoe assemblies 36 initially makecontact with the wallboard 26 and compress it an initial 0.010″. In thismanner, the upper shoe assemblies 36 to not dig into or put divots inthe wallboard 26 with a leading edge of the upper shoe assembly 36.

The lower shoes assemblies 54, as they pass around the second end 41 ofthe lower press assembly 24, as viewed in FIG. 12, are brought intoparallel relationship with the wallboard 26 and contact wallboard 26prior to the upper shoe assemblies 36 contacting the wallboard 26. Inthis manner, the lower shoe assemblies 54 provides support for thewallboard 26 and an opposing force for the upper shoe assembly 36 whenit makes initial contact with the wallboard 26 and begins compressingthe wallboard 26. Additionally, in order to prevent a preceding lowershoe assembly 54, labeled M in FIG. 12, from being forced into thewallboard 26 by the support surface 204 (if the support surface were notarcuate) a trailing lower shoe assembly 54, labeled N in FIG. 12, thesupport surface 204 is made arcuate such that the center of the arcformed by the surface 204 is the center of the bore 108.

Referring to FIG. 12, as the wallboard 26 traverses from right to left,the upper shoe assemblies 36 are moved from an initial impression of0.010″ near a point X to a final impression of 0.0102″ near a point Ywith the horizontal length between points X and Y preferably being about67″. This is accomplished by a taper along the bottom plates 30 and 32which force the upper shoe assemblies 36 into the wallboard by virtue ofcontact with the bearings 78 and 84. After point Y, the plates 30 and 32provide a taper that brings the upper shoe assemblies 36 out of contactwith the wallboard 26. A takeout conveyor 28 removes the wallboard 26from the press 20.

In a further preferred aspect of the invention, the lateral edges offinished lengths of wallboard are wrapped with paper to furtherstrengthen the edge of the wallboard.

While the specific embodiments have been illustrated and described,numerous modifications come to mind without significantly departing fromthe spirit of the invention, and the scope of protection is only limitedby the scope of the accompanying claims.

1. A method of making wallboard comprising: providing an unfinishedlength of wallboard that has a recess along its longitudinal edges byconveying it upon a conveyor in a first direction; and forming recessesin the unfinished length of wallboard at both lateral edges thereof;selecting an apparatus for forming the recess from a plurality ofdevices for forming the recess; forming the recess with the selectedapparatus; and separating the unfinished length of wallboard at alocation of the recess to form finished lengths of wallboard, such thatthe finished lengths of wallboard have recessed lateral edges.
 2. Themethod of claim 1 wherein the step of selecting an apparatus comprisesthe step of lowering the apparatus to contact the wallboard.
 3. Themethod of claim 1 wherein the step of selecting an apparatus furthercomprises moving the apparatus laterally to a desired location forforming the recess.
 4. The method of claim 1 wherein the wallboardprovided is partially cured gypsum wallboard.
 5. The method of claim 1wherein the step of forming the recess with the selected apparatuscomprises the step of gradually compressing the wallboard along thedesired location of the recess as the wallboard is conveyed in adirection generally parallel to the recess.
 6. The method of claim 1wherein the step of forming the recess with the selected apparatuscomprises the step of forming the recess with the selected apparatuswhile moving the wallboard in a direction generally perpendicular to thefirst direction
 7. The method of claim 1 wherein the step of forming therecess with the selected apparatus comprises the step of continuallyincreasing the recess on the wallboard as the wallboard moves in adirection parallel to the recess.
 8. The method of claim 1 wherein thestep of selecting an apparatus for forming the recess from a pluralityof device for forming the recess comprises the step of selecting aplurality of apparatus for forming a plurality of recesses.
 9. A methodof making wallboard comprising: forming a continuous slab of wallboardhaving opposed face surfaces bordered by a pair of longitudinal sideedges; forming longitudinal recessed areas along the side edges on afirst face of the wallboard; cutting the wallboard to a first,unfinished length; forming recesses in the wallboard at lateral edges ofthe unfinished length and forming at least one recess in the unfinishedlength of wallboard generally parallel to and offset from the lateraledges; and cutting the unfinished length of wallboard at a location ofthe recess such that the finished lengths of wallboard have recessedlateral edges.
 10. The method of claim 9 further comprising the step ofselecting an apparatus for forming the recess from a plurality of devicefor forming the recess.
 11. The method of claim 10 wherein the step ofselecting an apparatus for forming the recess from a plurality ofapparatus for forming the recess comprises the step of lowering theapparatus to contact the wallboard.
 12. The method of claim 11 furthercomprising the step of selecting the apparatus from a plurality ofapparatus adapted to be lowered to contact the wallboard.
 13. The methodof claim 9 further comprising the step of positioning the apparatus to adesired location of the recess.
 14. The method of claim 13 wherein thestep of positioning the apparatus further comprises moving the apparatuslaterally to a desired location for forming the recess.
 15. The methodof claim 14 wherein the step of positioning the apparatus for formingthe recess comprises the step of lowering the apparatus to contact thewallboard.
 16. The method of claim 15 further comprising the step ofselecting the apparatus from a plurality of apparatus adapted to belowered to contact the wallboard.
 17. The method of claim 9 wherein thewallboard provided is partially cured gypsum wallboard.
 18. The methodof claim 9 wherein the step of forming the recess with the selectedapparatus comprises the step of gradually compressing the wallboardalong the desired location of the recess as the wallboard is conveyed ina direction generally parallel to the recess.
 19. The method of claim 9wherein the step of forming the recess with the selected apparatuscomprises the step of forming the recess with the selected apparatuswhile moving the wallboard in a direction generally perpendicular to thefirst direction
 20. The method of claim 9 wherein the step of formingthe recess with the selected apparatus comprises the step of continuallyincreasing the on the wallboard as the wallboard moves in a directionparallel to the recess.
 21. A device for forming recesses in anunfinished length of wallboard: a first press located at a first lateraledge of the unfinished length of wallboard; a second press located at asecond lateral edge of the unfinished length of wallboard opposite thefirst lateral edge; a third press located between the first and secondpress; whereby as unfinished length of wallboard is fed into the first,second and third presses the first press forms a recess along the firstlateral edge, the second press forms a recess along the second lateraledge and the third press forms a recess in the wallboard generallyparallel to the first recess and between the first and second lateraledges.
 22. The device of claim 21 further comprising one or moreadditional presses for forming one or more additional recesses in theunfinished length of wallboard.
 23. The device of claim 21 wherein thepresses provide gradually increasing pressure to the wallboard as thewallboard is conveyed toward the presses.
 24. The device of claim 21wherein the presses each comprise an upper and lower surface that tapertoward one another gradually over not less than 6 inches of length. 25.The device of claim 24 wherein the surfaces are attached to movingchains which support and compress the wallboard.
 26. The device of claim24 wherein the upper surface defines the desired taper to be imprintedinto the wallboard and the lower surface is a generally flat surface.27. The device of claim 24 wherein the upper surfaces may be selectivelyraised and lowered to bring the upper surface into and out of contactwith the wallboard.
 28. The device of claim 24 wherein at least one ofthe upper surfaces are moveable laterally to place the press in adesired location.
 29. A device for forming recesses in an unfinishedlength wallboard: a casting conveyor for forming a continuous slab ofwallboard from a slurry, the wallboard having inner and outer papersurfaces bordered by a pair of longitudinal side edges, the conveyorhaving shaped recess formers along the sides thereof to form recesses inthe longitudinal edges; a cutting system adjacent to the end of theconveyor for cutting the wallboard slab to unfinished lengths; a lateraledge forming system for forming lateral recessed areas on the unfinishedlengths at the cut lateral edges; a first press located at a firstlateral edge of the unfinished length of wallboard; a second presslocated at a second lateral edge of the unfinished length of wallboardopposite the first lateral edge; a third press located between the firstand second press; whereby when an unfinished length of wallboard is fedinto the first, second and third presses the first press forms a recessalong the first lateral edge, the second press forms a recess along thesecond lateral edge and the third press forms a recess in the wallboardgenerally parallel to the first recess and between the first and secondlateral edges.
 30. The device of claim 29 further comprising one or moreadditional presses for forming one or more additional recesses in theunfinished length of wallboard.
 31. The device of claim 29 wherein thepresses provide gradually increasing pressure to the wallboard as thewallboard is conveyed toward the presses.
 32. The device of claim 29wherein the presses each comprise an upper and lower surface that tapertoward one another gradually over not less than 6 inches of length. 33.The device of claim 32 wherein the surfaces are attached to movingchains which support and compress the wallboard.
 34. The device of claim32 wherein the upper surface defines the desired taper to be imprintedinto the wallboard and the lower surface is a generally flat surface.35. The device of claim 32 wherein the upper surfaces may be selectivelyraised and lowered to bring the upper surface into and out of contactwith the wallboard.
 36. The device of claim 32 wherein at least one ofthe upper surfaces are moveable laterally to place the press in adesired location.
 37. A method of making wallboard comprising: providingan unfinished length of wallboard; providing a press assembly comprisingan upper assembly and a lower assembly, wherein the upper assemblycomprises an infinite loop having an exterior surface rotatable aboutthe upper press assembly and the lower press assembly comprises aninfinite loop having an exterior surface rotatable about the lowerassembly, wherein the upper and lower press assemblies are placedopposite one another wherein a gap between the exterior surfaces of theloops of the upper and lower press assemblies gradually tapers from afirst distance at a first end of the press assembly to a second, closerdistance; rotating the loops of the upper and lower press assemblies;and moving the unfinished length of wallboard between the upper andlower press assemblies by contacting the wallboard between rotatingloops and moving the wallboard through the tapered gap.
 38. A device forforming recesses in a length of wallboard comprising: a press assemblycomprising an upper press assembly and a lower press assembly, the upperpress assembly comprising an infinite loop with an exterior surface andthe lower assembly comprising an infinite loop with an exterior surface,the infinite loops being rotatable about their respective upper or lowerpress assembly, the press assemblies being placed adjacent one anotherto define a gap therebetween, the gap being tapered such that it iswider at a first end of the press assembly and narrows to a smallerdimension.